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Jimusaria is the first reported Chinese dicynodont, previously only known from Xinjiang. Here we refer two specimens from the Naobaogou Formation, Nei Mongol, China to Jimusaria based on the following features: squamosal separated from supraoccipital by tabular, tabular contacting opisthotic, sharp and thin lateral dentary shelf expanding anteriorly into a thick swelling, nasals fused as single element, rod-like medial bar formed by footplate of epipterygoid connecting to the parabasisphenoid and periotic medially. A new species, J. monanensis, is named based on the diagnostic characters on these two specimens such as distinct caniniform buttress lacking posteroventral furrow, naso-frontal suture forming an anterior directed sharp angle, and converging ventral ridges on posterior portion of anterior pterygoid rami. In Jimusaria, the epipterygoid posteromedially contacts the parabasisphenoid and the periotic as a rod-like bar, a unique morphology unknown in any other dicynodonts. This structure probably increases the stability of the palatal complex. A similar structure might also appear in other dicynodonts as a cartilage connection. The new occurrence of Jimusaria increases the diversity of the tetrapod assemblage from the Naobaogou Formation, and further strengthens the connection between the tetrapod faunas from Nei Mongol and Xinjiang. Based on the current record, Jimusaria is one of the few tetrapod genera which survived in the end-Permian mass extinction. [ABSTRACT FROM AUTHOR]

There is still considerable controversy surrounding the impact of mastication on obesity. The aim of this study was to identify the interplay between the masticatory muscles, teeth, and general muscular fitness and how they contribute to body adiposity in a general German population. This cross-sectional study included 616 participants (300 male, 316 female, age 31–93 years) from the population-based Study of Health in Pomerania. The cross-sectional areas of the masseter, medial and lateral pterygoid muscles were measured using magnetic resonance imaging (MRI), muscular fitness assessed by hand grip strength (HGS) and body fat distribution was measured by bioelectrical impedance analysis (BIA) and MRI. The overall prevalence of obesity was high in our cohort. The cross-sectional area of the masseter muscles was positively associated with the number of teeth, body mass index (BMI) and HGS, and negatively associated with the BIA-assessed body fat when adjusted for age, sex, teeth, and BMI. Especially the correlation was strong (p < 0.001). Analogous relationships were observed between the masseter, HGS and MRI-assessed subcutaneous fat. These associations were most pronounced with masseter, but also significant with both pterygoid muscles. Though the masticatory muscles were affected by the number of teeth, teeth had no impact on the relations between masseter muscle and adiposity. Physical fitness and masticatory performance are associated with body shape, controlled and directed by the relevant muscles. [ABSTRACT FROM AUTHOR]

Pterygoid implant placement has not been a common treatment modality to manage the atrophic posterior maxilla. This randomized, controlled clinical trial evaluated the accuracy of dynamic navigation using trace registration (TR) technology in pterygoid implant placement when compared to free-hand surgery. Partially edentulous patients requiring at least one pterygoid implant to rehabilitate the atrophic posterior maxilla were included. Implant accuracy (in a prosthetically directed context) and the relation of the placed implants to the greater palatine canal (GPC) were evaluated using EvaluNav to compare the preoperative CBCT plan with the postoperative CBCT implant location. Osseointegration success, mucosal thickness, implant length, time spent for surgical placement, and ease of prosthetic restorability via degree of multi-unit abutment angulation were assessed. A total of 63 pterygoid implants were placed (31 using TR, 32 using free-hand) in 39 partially edentulous patients. Mean deviations between the planned and actual position for TR-placed implants were 0.66 mm at the coronal level, 1.13 mm at the apical level, 0.67 mm in depth, and 2.64 degrees of angular deviation, compared to 1.54 mm, 2.73 mm, 1.17 mm, and 12.49 degrees, respectively, for free-hand implants. In relation to the GPC, TR implants were more accurate when compared to the presurgical plan and took less surgical time. The mean mucosal thickness measured for all implants was 5.41 mm. Most implants were 15 to 18 mm long, and most prostheses (92%) could be accommodated by a 17- or 30-degree multi-unit screw-retained abutment. TR implants had greater short-term osseointegration success rates than free-hand implants (100% vs 93.75%). Pterygoid implant surgery can be a predictable and successful modality for prosthetically directed implant rehabilitation in the atrophic posterior maxilla, is more accurate than free-hand surgery, and takes less time when using dynamic navigation via TR. [ABSTRACT FROM AUTHOR]

Marcus Gunn jaw wink phenomenon or Trigeminal oculomotor synkinesis, is a congenital disorder in which the upper lid moves synkinetically in response to jaw movement during chewing. The term synkinesis describes the simultaneous movement or a coordinated sequence of movements of muscles, which are supplied by different nerves or by separate peripheral branches of the same nerve. Although it rarely manifests bilaterally, it is typically unilateral. In 1883, Dr Robert Marcus Gunn, a Scottish Ophthalmologist described a 15-year-old girl with a peculiar type of congenital ptosis that included an associated winking motion of the affected eyelid on the movement of the jaw. It is known to affect both men and women equally. This phenomenon has been reported to be a similar phenomenon affecting 2-13% of all cases of congenital ptosis. It can be congenital or acquired, for example through trauma. The Congenital Marcus Gunn jaw wink phenomenon is thought to arise from the connection between the branch of the trigeminal nerve (responsible for chewing) supplying the middle or lateral pterygoid muscle and the branch of the oculomotor nerve supplying the upper superior levator ocular defect. Here we present a case report of Marcus Gunn's Jaw-Winking Synkinesis in congenital ptosis. [ABSTRACT FROM AUTHOR]

The precise definition of the accessory meningeal artery was not available until 1961. It can originate from the maxillary artery or middle meningeal artery and supplies the meatus and membranous portion of the auditory tube, the lateral pharyngeal muscle, and the medial pterygoid muscle; Laterally, it supplies the lateral pterygoid muscle, the extracranial part of the mandibular nerve, the pterygoid venous plexus, and the sphenoid periosteum. Here, we present a 70-year-old male patient who applied to the neurosurgery clinic with complaints of chronic headaches and dizziness. Magnetic resonance angiography and computed tomography angiography showed hypoplasic appearance of the left internal carotid artery and an enlarged accessory meningeal artery variant merging with its ophthalmic segment. [ABSTRACT FROM AUTHOR]

Summary: Regional and systemic disorders of myopathic or neurogenic cause affecting the masticatory muscles have been reported or suspected in horses. The primary masticatory muscles include the masseter, temporalis, lateral and medial pterygoid muscles. The masseter muscle is the largest of the primary masticatory muscles and the most affected based on sporadic reports. This is a brief review of disorders involving the masseter muscle. [ABSTRACT FROM AUTHOR]

Objectives: The purpose of this study was to elucidate how masticatory muscles are involved in the generation of occlusal force. Materials and Methods: The experiment was conducted by fabricating an experimental apparatus for a unilateral occlusion model with the masticatory muscles imparted. The experimental apparatus was fabricated by enlarging the lateral photograph of a dried adult skull specimen 3.5 times larger than that of a standard adult and drawing the outlines of the maxilla and mandible, canines and molars of the upper and lower jaws, and temporomandibular joint on a wooden board. The masticatory muscles used in the experiment were the masseter muscle, the temporalis muscle (anterior and posterior muscle bundles), and the lateral pterygoid muscle. For the measurement of the contractile force of the masticatory muscle, we used the spring scale. For the food, we used cut plastic cylinders. Results: The results of the experiment revealed the following: First, the occlusal force was generated under the condition that the contraction forces of all the masticatory muscles were balanced. Second, when the occlusal force was applied to food, the occlusal planes of the upper and lower jaws were parallel. Third, the occlusal force occurred perpendicular to the occlusal plane. Fourth, the occlusal force was generated with a force greater than the contraction force of the individual masticatory muscles. And finally, even if occlusal force was applied to the food, the occlusal force did not load the temporomandibular joint. Conclusion: Occlusal force is not generated by the action of a single masticatory muscle but under the balanced contractile force of all masticatory muscles. The occlusal force then emerges with a force greater than the contraction force of all the masticatory muscles, and its direction occurs perpendicular to the occlusal plane. [ABSTRACT FROM AUTHOR]

Botulinum toxin type A (BTX-A) injection using nerve stimulation or electromyography for recurrent temporomandibular joint (TMJ) dislocation has been reported for several years. However, using the available equipment like a nerve stimulator or an electromyograph is uncommon, and ultrasound guidance is convenient and requires no additional resources. In this report, we used ultrasound as a tool to achieve BTX-A injections in a patient with a traumatic brain injury to treat her TMJ dislocation. One week after the injections, she had no more dislocation. She remained symptom free during the 3 months of follow-up, and her clinical symptoms improved without significant complications. This is the first report using ultrasound guidance for BTX-A injections to treat recurrent TMJ dislocation. This treatment is an effective and safe technique that could be performed timely and locally without referral to a center with electromyography facilities. [ABSTRACT FROM AUTHOR]

Background: To research the pathological and clinical staging uses of arterial spin labeling (ASL) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). Materials and methods: 64 newly diagnosed nasopharyngeal carcinoma (NPC) patients were enrolled from December 2020 to January 2022, and 3.0 T MRI (Discovery 750W, GE Healthcare, USA) were used for ASL and DCE-MRI scans. The DCE-MRI and ASL raw data were processed post-acquisition on the GE image processing workstation (GE Healthcare, ADW 4.7, USA). The volume transfer constant (Ktrans), blood flow (BF), and accompanying pseudo-color images were generated automatically. Draw the region of interest (ROIs), and the Ktrans and BF values for each ROI were recorded separately. Based on pathological information and the most recent AJCC staging criteria, patients were divided into low T stage groups = T1–2 and high T stage groups = T3–4, low N stage groups = N0–1 and high N stage groups = N2–3, and low AJCC stage group = stage I–II and high AJCC stage group = stage III–IV. The association between the Ktranst and BF parameters and the T, N, and AJCC stages was compared using an independent sample t-test. Using a receiver operating characteristic (ROC) curve, the sensitivity, specificity, and AUC of Ktranst, BFt, and their combined use in T and AJCC staging of NPC were investigated and assessed. Result: The tumor-BF (BFt) (t = − 4.905, P < 0.001) and tumor-Ktrans (Ktranst) (t = − 3.113, P = 0.003) in the high T stage group were significantly higher than those in the low T stage group. The Ktranst in the high N stage group was significantly higher than that in the low N stage group (t = − 2.071, P = 0.042). The BFt (t = − 3.949, P < 0.001) and Ktranst (t = − 4.467, P < 0.001) in the high AJCC stage group were significantly higher than those in the low AJCC stage group. BFt was moderately positively correlated with the T stage (r = 0.529, P < 0.001) and AJCC stage (r = 0.445, P < 0.001). Ktranst was moderately positively correlated with T staging (r = 0.368), N staging (r = 0.254), and AJCC staging (r = 0.411). There was also a positive correlation between BF and Ktrans in gross tumor volume (GTV) (r = 0.540, P < 0.001), parotid (r = 0.323, P < 0.009) and lateral pterygoid muscle (r = 0.445, P < 0.001). The sensitivity of the combined application of Ktranst and BFt for AJCC staging increased from 76.5 and 78.4 to 86.3%, and the AUC value increased from 0.795 and 0.819 to 0.843, respectively. Conclusion: Combining Ktrans and BF measures may make it possible to identify the clinical stages in NPC patients. [ABSTRACT FROM AUTHOR]

The purpose of this study was to compare the effectiveness of arthroscopic-assisted lateral pterygoid muscle release versus scarification of retrodiscal tissues in the treatment of temporomandibular joint internal derangement. A prospective, comparative, randomized clinical trial involved 16 patients with TMJ internal derangement. Arthroscopic assisted release of lateral pterygoid muscle was assigned to one group of patients (Group I). Group II patients received arthroscopic assisted scarification of retrodiscal tissues. Data collected through functional examination including visual analogue scale (VAS), maximum mouth opening, lateral excursion, and clicking sound immediately and after 3, 6, and 12 months. Pre- and post-operative MRI was used to assess disc position. The VAS scores decreased in both groups at the end of the follow-up period (0.45 vs 6.75, and 1.13 vs 6.50 in group I and II respectively; P<0.001). The maximum mouth opening improved to 32.9.50 ± 1.69 mm in group I, and 30.49 ± 0.93 in group II (P<0.001). Lateral excursion improved in both groups (P<0.001). Clicking sounds disappeared in all patients. Within the limitations of the study, it seems that arthroscopic assisted release of lateral pterygoid and scarification of retrodiscal tissues may be beneficial in management of anteriorly displaced discs that don't respond to conservative treatments. [ABSTRACT FROM AUTHOR]

Background: Temporomandibular joint disorders (TMDs) are the most common cause of non-odontogenic pain in the maxillofacial region. Internal derangement (ID) is one of the most prevalent causes of TMDs, and disc displacement is recognized as the most common ID. The masticatory muscles are among anatomical structures involved in TMDs that may be affected by ID. Objectives: This study aimed to evaluate the correlation between the masticatory muscle dimensions and ID of temporomandibular joints using magnetic resonance imaging (MRI). Patients and Methods: This cross-sectional study was conducted on the MRI images of 145 patients, retrieved from the archives of the MRI diagnostic and research center during 2020 - 2021. The patients were categorized into three main groups of normal disc position (NP) (n = 42), disc displacement with reduction (DDR) (n = 54), and disc displacement without reduction (DDWR) (n = 49). The maximum width and height of the masseter and medial pterygoid muscles and the maximum height and length of the superior and inferior heads of the lateral pterygoid muscle were measured on MRI images for each of the groups. Data were analyzed using t-test, Pearson's correlation test, ANOVA test, and Tukey's test (alpha < 0.05). Results: Significant differences were observed between the NP, DDR, and DDWR groups regarding the height (P < 0.001) and length (P< 0.001) of the superior head of the lateral pterygoid muscle; both parameters were significantly higher in the NP group, followed by the DDR and DDWR groups (P < 0.05). The dimensions of masticatory muscles were significantly greater in males than females (P < 0.05), except for the width of the medial pterygoid muscle (P = 0.064). The height of the masseter muscle (r = 0.190, P = 0.022) and the medial pterygoid muscle (r = 0.166, P = 0.046) was significantly correlated with age. Conclusion: Significant correlations were found between the height and length of the superior head of the lateral pterygoid muscle and ID of TMJ; the corresponding values were lower in the DDWR group compared to the DDR and NP groups, respectively. [ABSTRACT FROM AUTHOR]

Objectives: Magnetic resonance imaging (MRI) is useful for assessing temporomandibular disorders (TMDs). However, few studies have attempted texture analysis of the lateral pterygoid muscle in patients with rheumatoid arthritis (RA). This study aims to investigate the usefulness of MRI texture analysis of the lateral pterygoid muscle of patients with RA of the temporomandibular joint (TMJ). Methods: We analyzed the data from 36 patients (18 non-RA patients and 18 RA patients) who complained of pain and underwent MRI between April 2008 and August 2021. From the MRI scans of these patients, 279 radiomics features were extracted using STIR image data of the ROIs on the lateral pterygoid muscle of patients with RA and analyzed using MaZda ver. 3.3. Seven gray-level co-occurrence matrix features (Sum entropy, Sum variance) were picked up using the Fisher coefficient, for comparison between the RA and non-RA groups. Data analysis was performed using the Mann–Whitney U test A P value of < 0.05 was considered as statistically significant. Results: All seven lateral pterygoid muscle radiomic features indicated significant differences between the non-RA and RA groups (P < 0.05). Conclusion: MRI texture analysis shows potential for application in radiomics diagnosis of RA in TMJ. [ABSTRACT FROM AUTHOR]

Backgrounds: Despite publication of international guidelines, there are notable controversial points of clinical target volume (CTV) delineation in nasopharyngeal carcinoma (NPC). Recently, scholars proposed a novel way of delineation of CTV in NPC—individualization of CTV delineation based on T classification and spread patterns, which yielded excellent long-term local control with limited late toxicities. The aim of this study was to clarify the anatomic patterns and pathways of local recurrence of NPC and provide a clinical reference for the delineation of CTV. Methods: A total of 869 patients with non-metastatic NPC were treated with intensity-modulated radiation therapy (IMRT) at our institution between 2009 and 2010. Among the 57 cases of local/locoregional recurrence, 52 cases with traceable radiotherapy plans and magnetic resonance imaging at the time of the first diagnosis of recurrence were included. Anatomical structures and gross tumor volume of local recurrence were contoured. The incidence of relapse of each anatomic structure, route of local recurrence, and their correlation were analyzed. Results: Locally advanced disease had a significantly increased risk of recurrence in the posterior nasal cavity and a trend towards higher risk of recurrence in the clivus, lateral pterygoid muscle, and hypoglossal canal. Based on the incidence of local recurrence, we constructed a high-risk map for the early and locally advanced stages. Local recurrences were classified into five routes, where anterior extension accounted for the majority (30.8%), and caudal tumor extension pathway had the lowest incidence (5.8%). There was a significant correlation between the local recurrences of neural foramina and neighboring anatomical structures along each pathway. All cases relapsed at unilateral cavernous sinus, most at the same side of primary tumor. Based on our findings, we proposed some suggestions on delineations of CTV, based on T classification and local extension pattern. Conclusions: Local recurrence of NPC varied according to T classification, followed a stepwise pattern, spread via neural foramina, and recurred at ipsilateral cavernous sinus. This provides meaningful clinical evidence for delineation of CTV, especially individualized delineation. [ABSTRACT FROM AUTHOR]

Background: Typical Lemierre's syndrome is usually secondary to an oropharyngeal infection. Recently, several cases following a primary infection site other than the oropharynx have been reported as atypical Lemierre's syndrome; although, these primary lesions are limited to the head and neck. This is the first case potentially sequential to infectious foci outside the head and neck. Case presentation: We describe an atypical Lemierre's syndrome in a 72-year-old woman with rheumatoid arthritis, which occurred during the treatment of Streptococcus anginosus bacteremia acquired from a sacral ulcer infection related to rheumatoid vasculitis. At first, the symptoms resolved after the initial administration of vancomycin for the bacteremia caused by methicillin-resistant Staphylococcus aureus and Streptococcus anginosus that entered via a sacral ulcer. On the 8th day, the patient developed a fever of 40 °C and unexpectedly required 10 L of oxygen due to rapid deterioration of oxygenation temporarily. Immediately contrast-enhanced computed tomography was performed to investigate systemic thrombosis including pulmonary embolism. Afterward, the newly formed thrombi at the right external jugular vein, bilateral internal jugular veins, and the right small saphenous vein were detected, and apixaban was started. On the 9th day, the patient again had an intermittent fever of 39.7 °C, and continuous Streptococcus anginosus bacteremia was revealed; subsequently, clindamycin was administered. On the 10th day, she developed a left hemothorax; consequently, apixaban was discontinued, and a thoracic drain was inserted. She repeatedly had an intermittent fever of 40.3 °C, and contrast-enhanced computed tomography detected an abscess formation at the left parotid gland, pterygoid muscle group, and masseter muscle. After Lemierre's syndrome was diagnosed in combination with the abovementioned jugular vein thrombus, clindamycin was replaced with meropenem, and vancomycin was increased. Swelling of the lower part of the left ear became prominent with delay and peaked at approximately the 16th day. The subsequent treatment course was favorable, and she was discharged on the 41st day. Conclusion: Clinicians should consider Lemierre's syndrome as the differential diagnosis of internal jugular vein thrombosis occurring during sepsis, even though an antibiotic is administered or a primary infection site is anything besides the oropharynx. [ABSTRACT FROM AUTHOR]

Bite force is often associated with specific morphological features, such as sagittal crests. The presence of a pronounced sagittal crest in some tapirs (Perissodactyla: Tapiridae) was recently shown to be negatively correlated with hard‐object feeding, in contrast with similar cranial structures in carnivorans. The aim of this study was to investigate bite forces and sagittal crest heights across a wide range of modern and extinct tapirs and apply a comparative investigation to establish whether these features are correlated across a broad phylogenetic scope. We examined a sample of 71 specimens representing 15 tapir species (5 extant, 10 extinct) using the dry‐skull method, linear measurements of cranial features, phylogenetic reconstruction, and comparative analyses. Tapirs were found to exhibit variation in bite force and sagittal crest height across their phylogeny and between different biogeographical realms, with high‐crested morphologies occurring mostly in Neotropical species. The highest bite forces within tapirs appear to be driven by estimates for the masseter–pterygoid muscle complex, rather than predicted forces for the temporalis muscle. Our results demonstrate that relative sagittal crest height is poorly correlated with relative cranial bite force, suggesting high force application is not a driver for pronounced sagittal crests in this sample. The divergent biomechanical capabilities of different contemporaneous tapirids may have allowed multiple species to occupy overlapping territories and partition resources to avoid excess competition. Bite forces in tapirs peak in Pleistocene species, independent of body size, suggesting possible dietary shifts as a potential result of climatic changes during this epoch. [ABSTRACT FROM AUTHOR]

The group of Permo-Carboniferous tetrapods known as Recumbirostra have recently been hypothesized to represent the earliest radiation of fossorial reptiles. Therefore, understanding the anatomy and diversity of this clade is essential to understanding the origin and early evolution of amniotes. Here, we redescribe the diminutive 'microsaur' Odonterpeton triangulare from the Moscovian-age deposit of Linton, Ohio, revealing new details on the structure of the cranium and palate, including the presence of a conspicuous transverse flange of the pterygoid, which is a feature traditionally associated with early amniotes. Phylogenetic analysis supports the placement of Odonterpeton triangulare within Recumbirostra as sister taxon to the recently described Joermungandr bolti from the slightly older Mazon Creek, Illinois, Lagerstätte. Together, these two diminutive recumbirostrans are placed in an Odonterpetidae clade. Furthermore, we provide a discussion of newly recognized anatomical features in recumbirostrans and discuss major features of recumbirostran phylogeny. We designate a new recumbirostran clade, Chthonosauria (Brachystelechidae + Molgophidae), which is supported by a number of shared derived cranial features. [ABSTRACT FROM AUTHOR]

Objective: There have been few studies on the anatomy of palatine aponeurosis (PA). Herein, we elucidated the relationship between the PA and soft palate muscles and pharyngeal muscles. Design: Two cadaveric specimens were dissected to observe the gross anatomy of the PA. Six cadaveric specimens were processed and scanned by micro-computed tomography to determine the elaborate anatomy. Images were exported to Mimics software to reconstruct a three-dimensional model. Results: The PA covered the anterior (32.1%-38.8%) of the soft palate, extending from the tensor veli palatini (TVP) and connecting to 3 muscles: palatopharyngeus (PP), uvula muscle, and superior pharyngeal constrictor (SC). The SC and PP are attached to the PA on the medial side of the pterygoid hamulus. SC muscle fibers were attached to the hamulus, forming a distinct gap between the hamulus. Some muscle fibers of the PP and uvula originated from the PA. The PA extended from the TVP to the midline and the posterior edge of the hard palate. The PA was not uniformly distributed, which was complementary to the attached muscles in thickness. Conclusions: PA, as a flexible fibrous membrane, maintains the shape of the soft palate. It extends from the TVP and covers anteriorly about one-third of the soft palate. The PA provides a platform for the soft palate muscles and pharyngeal muscles, connecting to the PP, uvula muscle, and SC. These muscles are important for palatopharyngeal closure and middle-ear function. It is necessary to minimize the damage to the PA during surgical interventions. [ABSTRACT FROM AUTHOR]

This study describes the clinical anatomical topography and relationship of the terminal branches of the maxillary artery to the bony wall of the maxillary sinus in the pterygopalatine fossa (PPF) to estimate the bleeding risk during surgical interventions. Using contrasted computer tomography records, (i) the route of the maxillary artery in the infratemporal fossa, (ii) the number of the arteries in the critical PPF surgery plane, (iii) the diameter of the largest artery in the area and (iv) its relation to the posterior wall of the maxillary sinus were examined. Furthermore, measurements were extended with (v) the minerality of the bony posterior wall of the maxillary sinus on bone-window images. For statistical analyses Student's t- and Fisher-test were applied. 50 patients (n = 50, 100 cases including both sides) were examined in this study. The maxillary artery reached the pterygomaxillary fissure on the lateral side of the lateral pterygoid muscle in 56% of the cases (n = 32), in 37% (n = 23) on its medial side and in 7% (n = 4) on both sides. The number of arteries at the level of the Vidian canal in the PPF varied between 1 and 4 with a median of 2. The diameter of the biggest branch was 1.2–4.7 mm, the median diameter was 1.90 mm. In 41% (n = 30) of the cases the biggest artery directly contacted the posterior wall of the maxillary sinus, and the mineral density of the posterior wall was decreased in 14.3% (n = 12) of all investigated cases. The present description and statistical analysis of the vasculature of the PPF optimizes operative planning—like clip size or the type and direction of the surgical approach—in this hidden and deep head/neck region. [ABSTRACT FROM AUTHOR]

Objective: This retrospective study aimed to analyse the anatomical dimensions of the pterygomaxillary region, installation angulations of pterygoid implants and bone density in the pterygoid pillar region by cone beam computed tomography (CBCT) examinations used in planning dental rehabilitation with implant‐supported prostheses in patients with atrophic jaws. Materials and Methods: We analysed 360 CBCTs of patients with atrophic jaws using Xoran® software v.3.1.62 (Xoran Technologies). In addition, the angulation of virtual implants installed in the pterygomaxillary region was analysed in relation to the Frankfurt plan, as well as the length required for the installation of implants in this region. Results: The implant length installed in the pterygoid pillar varied between 13 and 20 mm, with an average of 16.17 mm (SD 2.16 mm). The pterygoid implant angulation on the latero‐lateral axis (frontal view) averaged 78.71° (SD. 3.58°) and 73.50° (SD 3.49°) in the anteroposterior direction (sagittal view). Bone density was found to be significantly higher in the pterygoid pillar region compared the maxillary tuberosity region (p < 0.05); the region of the tuberosity and pterygoid pillar had an average density value of 132.9 (SD 230.24) and 513.91 (SD 291.63) respectively. Conclusion: According to the results of this study, a pterygoid implant with a minimum length of 13 mm should be used in the pterygomaxillary region to reach the pterygoid bone pillar. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this study was to assess whether magnetic resonance imaging (MRI) texture features of the lateral pterygoid muscle can distinguish between rheumatoid arthritis (RA) and osteoarthritis (OA) of the temporomandibular joint (TMJ). Methods: The authors extracted 279 texture features from 36 patients with RA and OA from the region of interest set for the lateral pterygoid muscle on short tau inversion recovery (STIR) images using MaZda Ver.3.3. A total of 10 texture features were selected using Fisher's coefficients, as well as probability of error and average correlation coefficients. Data observed to have a non-normal distribution using the Kolmogorov-Smirnov test were compared using the Mann-Whitney U-test. Receiver operating characteristic (ROC) curves were used to assess the ability of the 10 texture features to distinguish RA and OA of the TMJ. Results: A total of 10 features (5 Correlation, 3 Run Length Nonuniformity, 1 Sigma, and 1 Teta) were selected from 279 texture features. These texture features revealed significant differences between the RA and OA groups (p < 0.01). The sensitivity, specificity, accuracy, and area under the ROC curve of the texture features for distinguishing RA from OA were 0.78-0.94, 0.89-1.0, 0.86-0.92, and 0.89-0.95, respectively. Conclusion: MRI texture analysis of the lateral pterygoid muscle may be useful for distinguishing between RA and OA of the TMJ. [ABSTRACT FROM AUTHOR]

The morphology of the mammalian chondrocranium appears to differ significantly from those of other amniotes, since the former possesses uniquely developed brain and cranial sensory organs. In particular, a question has long remained unanswered as to the developmental and evolutionary origins of a cartilaginous nodule called the ala hypochiasmatica. In this study, we investigated the embryonic origin of skeletal elements in the murine orbitotemporal region by combining genetic cell lineage analysis with detailed morphological observation. Our results showed that the mesodermal embryonic environment including the ala hypochiasmatica, which appeared as an isolated mesodermal distribution in the neural crest‐derived prechordal region, is formed as a part of the mesoderm that continued from the chordal region during early chondrocranial development. The mesoderm/neural crest cell boundary in the head mesenchyme is modified through development, resulting in the secondary mesodermal expansion to invade into the prechordal region. We thus revealed that the ala hypochiasmatica develops as the frontier of the mesodermal sheet stretched along the cephalic flexure. These results suggest that the mammalian ala hypochiasmatica has evolved from a part of the mesodermal primary cranial wall in ancestral amniotes. In addition, the endoskeletal elements in the orbitotemporal region, such as the orbital cartilage, suprapterygoid articulation of the palatoquadrate, and trabecula, some of which were once believed to represent primitive traits of amniotes and to be lost in the mammalian lineage, have been confirmed to exist in the mammalian cranium. Consequently, the mammalian chondrocranium can now be explained in relation to the pan‐amniote cranial configuration. [ABSTRACT FROM AUTHOR]

Objective Trigeminal neuralgia (TN) is a debilitating syndrome characterized by paroxysmal facial pain in one or more divisions of the trigeminal nerve. The etiology and treatment paradigms are still controversial. The endoscopically-assisted procedure has not yet been described in percutaneous procedures for TN. The aim of this study was to assess the utility and feasibility of endoscopic-assisted percutaneous approaches for trigeminal rhizotomy in TN. Methods This study comprised eight cadaveric sides heads that underwent an endoscopically assisted percutaneous approach using Hakanson's anterior puncture method for targeting the foramen ovale. Results V3 exiting the foramen ovale was easily visualized with the endoscope on all sides. While approaching the foramen ovale, distal branches of V3 such as the lingual and inferior alveolar nerves were first identified as they traveled between the medial and lateral pterygoid muscles. These branches were then traced proximally to the V3 trunk deep to the lateral pterygoid. Large arteries and veins were easily visualized and avoided in the trajectory to the foramen ovale. No gross injury to any neurovascular structure along the course of the needle insertion was identified. Conclusion We found that endoscopic-assisted percutaneous approach to the foramen ovale is feasible and allows for accurate canalization and anatomical identification of the precise location for rhizotomy under direct visualization. Such a procedure, after it is confirmed in patients, could offer a new technique for reducing unsuccessful canalization and could improve outcomes. [ABSTRACT FROM AUTHOR]

Temporomandibular disorder is a musculoskeletal disease with complex, multifactorial etiology regarding improper functioning of the stomatognathic system (masticatory muscles, temporomandibular joints, and surrounding structures). This article presents medical emergencies occurring among patients treated for temporomandibular disorders, which tend to constitute a severe difficulty for practitioners during their clinical practice. Examples of the most common emergencies of this type are disc displacement without reduction and a sudden contraction of the inferior part of the lateral pterygoid muscle. The latter occurs in cases of uncontrolled and incorrect use of the anterior repositioning splints and the hypertrophy of the coronoid process of the mandible. The sudden attacks of pain of secondary trigeminal neuralgia are also discussed in this article, together with their specific nature, which is significantly different from the nature of the pain of primary trigeminal neuralgia, yet the two types of neuralgia can be easily confused when the primary one takes the painful form. Subsequent emergencies discussed are myofascial pain syndrome, traumatic and inflammatory states of the temporomandibular joints, subluxation, and the consequences of intense occlusive parafunctions. Finally, the recommended therapeutic methods, which are used as part of the treatment in the cases of aforementioned emergencies, are described in this mini-review article, emphasizing that the implementation of the incorrect treatment and rehabilitation for emergencies of temporomandibular disorders may lead to permanent damage to the soft tissue structures of the temporomandibular joints. [ABSTRACT FROM AUTHOR]

Introduction: Radiation and intra-arterial cisplatin infusion chemotherapy (RADPLAT) for advanced maxillary sinus cancer has accumulated evidence as a treatment with fewer complications and better 5-year survival rates. In this study, we report a case in which pterygoid muscle necrosis occurred 6 months following RADPLAT treatment for maxillary sinus cancer. Case Presentation: The 45-year-old woman had a long history of taking immunosuppressants against rheumatoid arthritis (RA) prior to treatment. Although achieving complete response (CR) to RADPLAT, the patient developed trismus (1 fingerbreadth or less) 6 months following treatment. Abscess formation and recurrence were suspected from the imaging findings; however, the biopsy with endoscopy indicated necrotic tissue. Currently, 18 months have passed without cancer recurrence. Although trismus temporarily improved with rehabilitation, the width of the mouth opening is currently a few millimeters, so the patient can only take liquid food. Conclusion: Pterygoid muscle necrosis should be recognized as a new major complication. [ABSTRACT FROM AUTHOR]

Introduction: the aim of the present study was to determine the occurrence of syntopies between the maxillary artery (MA), the inferior alveolar nerve (IAN), the lingual nerve (LN), and the lateral pterygoid muscle (LPM); in addition, we also measured the trunk of the maxillary artery and its distance to anatomical landmarks. A cross-sectional study was performed with 35 hemifaces. Statistical analysis was performed on GraphPad Prism 6.01 (significance level and confidence interval set at 5% and 95%, respectively). The MA was predominantly located laterally to the IAN (R= 94,11%; L = 100%; p>0.05) and always located laterally to the LN (100% of cases, on both antimeres; p>0.05). The MA was mostly located superficially to the LPM (R= 83,33%; L= 88,23%; p>0.05). The mean thickness of the trunk of the MA on the cranio-caudal axis was of 2,23+/- 0,48mm (R) and 2,37+/- 0,65mm (L); and on the latero-medial axis of 1,76+/-0,39mm (R) and 1,72+/-0,49mm (L). The mean distance of the MA to the crest of the articular eminence was of 27,38+/-4,39mm (R) and of 26,84+/-4,46mm (L). All the aforementioned morphometric data showed non-significant results (p>0.05) when sides were compared. The mean distance between the MA and its first visible branch was of 11,78+/-5,79mm on the right side and of 8,44+/-5,99mm on the left side (p<0.05). [ABSTRACT FROM AUTHOR]

Fossils referable to the gorgonopsian Gorgonops sp. and to the dicynodont Endothiodon sp. are described from the Permian Madumabisa Mudstone Formation of the Mid-Zambezi Basin of southern Zambia. Specimens of the former taxon conform to recent diagnoses of the genus (e.g., five postcanine teeth, transverse flange of the pterygoid backswept, postorbital bar rugose and moderately expanded), but differ slightly from South African material in some respects (e.g., reduced dentition on the transverse flange of the pterygoid). Fossils of the latter are less complete, but show diagnostic features such as a dentary with numerous teeth, a ventral boss, and a shallow posterior dentary sulcus, oval palatine pads, and a narrow intertemporal region of the skull, although a species-level identification is not currently possible. Although the relevant fossils were never described, a vertebrate fossil assemblage including Endothiodon was previously reported from the Madumabisa Mudstone Formation in northern Zimbabwe (i.e., K5d), suggesting that this biozone was relatively broadly distributed across the Mid-Zambezi Basin. The Mid-Zambezi Basin of southern Zambia was previously demonstrated to host Guadalupian Tapinocephalus Assemblage Zone-equivalent strata, with rhinesuchids, burnetiamorphs, tapinocephalids, and dicynodonts recognized. The recognition of Lopingian Endothiodon Assemblage Zone-age rocks expands the stratigraphic range of vertebrate-bearing horizons in southern Zambia. [ABSTRACT FROM AUTHOR]

The anterior displacement of the articular disc is the most frequent cause of pathological alterations in the TMJ. Although it is an extremely common pathology, there is no certainty about the aetiopathogenesis of this disease. The main aim of the present report is to describe new anatomical findings that could help clarifying the aetiopathogenesis of this disease and determine a typology of treatment based on the cause of the disease. All the operative records of patients who underwent arthroscopic osteoplasty of the medial TMJ wall in our centre from January 2021 to September 2021 were reviewed and analysed to identify specific anatomical features observed in every procedure. Fifty-two joints were included for analysis in this study. Twenty-two joints were classified as Wilkes stages II-III and 30 as Wilkes stages IV-V. The most common complication observed in our sample was the dysaesthesias found in the temporal and preauricular regions. Other complications observed were frontal branch paresis (n = 2), intraoperative bleeding (n = 1), and postoperative malocclusion (n = 1). The compression of the superior head of pterygoid lateral muscle (SPLM) on the medial bony wall and the consequent muscle atrophy could be key for the aetiology of the anterior TMJ disc displacement. Therapeutic actions on the osseous and muscular component in this anatomical area could improve the outcomes of patients affected by TMJ internal derangement. A meticulous dissection of the fascia of the superior fascicle of the lateral pterygoid muscle allows a remodelling of the bone surfaces with minimal complications [ABSTRACT FROM AUTHOR]

Temporomandibular disorders affect between 5% and 12% of the population and present with symptoms such as headache, bruxism, pain at the temporomandibular joint, jaw popping or clicking, neck pain, tinnitus, dizziness, decreased hearing, and hyperacuity to sound. Common signs on physical examination include tenderness of the pterygoid muscles, temporomandibular joints, and temporalis muscles, and malocclusion of the jaw and crepitus. The diagnosis is based on history and physical examination; however, use of computed tomography or magnetic resonance imaging is recommended if the diagnosis is in doubt. Nonpharmacologic therapy includes patient education (e.g., good sleep hygiene, soft food diet), cognitive behavior therapy, and physical therapy. Pharmacologic therapy includes nonsteroidal anti-inflammatory drugs, cyclobenzaprine, tricyclic antidepressants, and gabapentin. Injections of the temporomandibular joints with sodium hyaluronate, platelet-rich plasma, and dextrose prolotherapy may be considered, but the evidence of benefit is weak. A referral to oral and maxillofacial surgery is indicated for refractory cases. (Am Fam Physician. 2023; 107(1):52–58. Copyright © 2023 American Academy of Family Physicians.) Temporomandibular disorders affect between 5% and 12% of the population and present with symptoms such as headache, bruxism, pain at the temporomandibular joint, jaw popping or clicking, neck pain, tinnitus, dizziness, decreased hearing, and hyperacuity to sound. Common signs on physical examination include tenderness of the pterygoid muscles, temporomandibular joints, and temporalis muscles, and malocclusion of the jaw and crepitus. The diagnosis is based on history and physical examination; however, use of computed tomography or magnetic resonance imaging is recommended if the diagnosis is in doubt. Nonpharmacologic therapy includes patient education (e.g., good sleep hygiene, soft food diet), cognitive behavior therapy, and physical therapy. Pharmacologic therapy includes nonsteroidal anti-inflammatory drugs, cyclobenzaprine, tricyclic antidepressants, and gabapentin. Injections of the temporomandibular joints with sodium hyaluronate, platelet-rich plasma, and dextrose prolotherapy may be considered, but the evidence of benefit is weak. A referral to oral and maxillofacial surgery is indicated for refractory cases. [ABSTRACT FROM AUTHOR]

Sternopygus sabaji, new species, is described from the Atlantic drainages of the Guiana Shield region of South America using traditional methods of morphometrics and meristics and microcomputed tomography (lCT) scans for osteological analysis. The new species is diagnosed from all other species of Sternopygus by the lack of dentition on the anteroventral surface of the endopterygoid and by the possession of a wider mouth. It further differs from its congeners by the following combination of characters: reduced humeral spot with low-contrast and poorly defined margins, possession of a light-colored mid-lateral stripe along posterior portion of lateral line, possession of 1-3 dark saddle-like markings along dorsum of smaller individuals, and a relatively low precaudal vertebrae count. This work provides the first description of a species of Sternopygus that is endemic to the Guiana Shield, joining S. astrabes and S. macrurus in elevating the species richness of the clade in that region to three species and the total number of valid Sternopygus to ten species. [ABSTRACT FROM AUTHOR]

We report a new small podocnemidid, Gestemys powelli gen. et sp. nov., based on one nearly complete skull, lower jaw, two shells, and remains of the appendicular skeleton belonging to two specimens from the Eocene Geste Formation of the San Antonio de la Cobres Basin, Salta Province, north-western Argentina. As in other podocnemidid genera, Gestemys exhibits a fully developed and medially extensive cavum pterygoidei, an incisura columellae auris enclosing the stapes and Eustachian tube, and lacks an exoccipital quadrate contact. Gestemys powelli bears a huge foramen palatinum posterius and a short pterygoid flange that does not reach the basisphenoid suture, exposing the cavum pterygoid. Phylogenetic analyses place Gestemys powelli as a member of Podocnemididae more closely related to Erymnochelyinae than Podocnemidinae. In regards to the palaeoenvironmental settings of the Palaeogene formations (Maíz Gordo and Geste) of north-western Argentina, at least two features differentiate the palaeoenvironment where G. powelli was recovered and those of other podocnemidid turtles from the Maíz Gordo Formation: 1) G. powelli was found in situ with very little re-working; and 2) in contrast to the muddy rocks indicating the marginal lacustrine setting and humid climate of the Maíz Gordo Formation, G. powelli is associated with a coarse-grained floodplain setting and a dry, temperate climate. Such differences highlight the contrasting environmental dynamics in which podocnemidid turtles lived during the Palaeogene. [ABSTRACT FROM AUTHOR]

Background: Speaking depends on refined control of jaw opening and closing movements. The medial pterygoid muscle (MPT), involved in jaw closing, and the lateral pterygoid muscle (LPT), involved in jaw opening, are two key mandibular muscles in mastication and are likely to be recruited for controlled movements in speech. Objectives: Three hypotheses were investigated, that during speech the MPT and LPT: (1) were both active, (2) but exhibited different patterns of activity, (3) which fluctuated with the vowels and consonants in speech. Methods: Intramuscular EMG recordings were made from the right inferior head of the LPT and/or the right MPT in five participants during production of 40 target nonsense words (NWs) consisting of three syllables in the form /V1C1V2 C2ə/ (V = vowel; C = consonant; ə = unstressed, reduced vowel), spoken by each participant 10 times per NW; analysis focussed on the target syllable, C1V2. Results: Both MPT and LPT exhibited robust increases in EMG activity during utterance of most NWs, relative to rest. Peak LPT activation was time‐locked to the final part of the target consonant (C1) interval when the jaw begins opening for the target vowel (V2), whereas peak MPT activation occurred around the temporal midpoint of V2, when the jaw begins closing for C2. EMG amplitude peaks differed in magnitude between "high" vowels, i.e., for which the tongue/jaw are high (e.g., in SEEK), and "low" vowels, i.e., for which the tongue/jaw are low (e.g., in SOCK). Conclusions: These novel findings suggest a key role for the LPT and MPT in the fine control of speech production. They imply that speech may impose major synergistic demands on the activities of the MPT and the LPT, and thereby provide insights into the possible interactions between speech activities and orofacial activities (e.g. mastication) and conditions (e.g. Temporomandibular Disorders) that involve the masticatory muscles. [ABSTRACT FROM AUTHOR]

Purpose: To describe the anatomic relationship of the lingual nerve with the lateral oropharyngeal structures. Methods: An anatomic dissection of the lateral oropharyngeal wall was conducted in eight sides from four fresh-frozen cadaveric heads. Small titanium clips were placed along the lingual nerve and the most anterior and medial border of the medial pterygoid muscle. Radiological reconstructions were employed for optimal visualization; the coronal view was preferred to resemble the surgical position. The distance between the lingual nerve and the medial pterygoid muscle at its upper and lower portion was measured radiologically. The trajectory angle of the lingual nerve with respect to the pterygomandibular raphe was obtained from the intersection between the vector generated between the clips connecting the upper and lower portion of the medial pterygoid muscle with the vector generated from the lingual nerve clips. Results: The mean distance from the upper portion of the medial pterygoid muscle and superior lingual nerve clips was 10.16 ± 2.18 mm (mean ± standard deviation), and the lower area of the medial pterygoid muscle to the lingual nerve was separated 5.05 ± 1.49 mm. The trajectory angle of the lingual nerve concerning to the vector that describes the upper portion of the most anterior and medial border of the medial pterygoid muscle with its lower part was 43.73º ± 11.29. Conclusions: The lingual nerve runs lateral to the lateral oropharyngeal wall, from superiorly–inferiorly and laterally–medially, and it is closer to it at its lower third. [ABSTRACT FROM AUTHOR]

The temnospondyl clade Amphibamiformes includes small newt-like forms that dwelled in freshwater lakes in the Pennsylvanian and Lower Permian of Europe and North America. Here we report a new genus and species, Piasimotriton kochovi, from the early Permian Boskovice Basin, Czech Republic. It has a unique combination of characters, among which the following ones rank as most important: (1) extremely elongated basipterygoid process forming a paired elongate facet for articulation with basal plate, (2) parasphenoid with broad and much abbreviated basal plate, about 2.5 times wider than long, (3) tooth crown with lateral crest, (4) premaxilla with 18 tiny teeth, and (5) a strong dermal ornament on the median skull elements. Piasimotriton kochovi has probably pedicellate teeth. Phylogenetic analysis finds Piasimotriton nests with the Melanerpeton clade with Melanerpeton, Leptorophus, and Schoenfelderpeton, with "Melanerpeton" gracile forming its sister taxon. The possession of various features that are also found in lissamphibians indicates a more widespread distribution of these within their putative stem-group. The stomach content of Piasimotriton kochovi consists of segmented thorax remains of small crustaceans. Piasimotriton probably competed with osteichthyans for arthropod prey and was only present in a short time interval of the lake's existence. [ABSTRACT FROM AUTHOR]

Stereospondyls underwent a global radiation in the Early Triassic, including an abundance of small-bodied taxa, which are otherwise rare throughout the Mesozoic. Lapillopsidae is one such clade and is presently known only from Australia and India. This clade's phylogenetic position, initially interpreted as micropholid dissorophoids and later as early diverging stereospondyls, remains uncertain. Although the latter interpretation is now widely accepted, lapillopsids' specific relationship to other Early Triassic clades remains unresolved; in particular, recent work suggested that Lapillopsidae nests within Lydekkerinidae. Here we describe Rhigerpeton isbelli, gen. et sp. nov., based on a partial skull from the lower Fremouw Formation of Antarctica that is diagnosed by a combination of features shared with at least some lapillopsids, such as a longitudinal ridge on the dorsal surface of the tabular, and features not found in lapillopsids but shared with some lydekkerinids, such as the retention of pterygoid denticles and a parachoanal tooth row (as in Lydekkerina, for example). A series of phylogenetic analyses confirm the lapillopsid affinities of R. isbelli but provide conflicting results regarding the polyphyly and/or paraphyly of Lydekkerinidae with respect to lapillopsids. The position of Lapillopsidae within Temnospondyli is highly sensitive to taxon sampling of other predominantly Early Triassic temnospondyls. The occurrence of a lapillopsid in Antarctica brings the documented temnospondyl diversity more in line with historically well-sampled portions of southern Pangea, but robust biogeographic comparisons remain hindered by the inability to resolve many historic Antarctic temnospondyl records to the finer taxonomic scales needed for robust biostratigraphy. [ABSTRACT FROM AUTHOR]

Purpose: Inferior alveolar nerve (IAN) and lingual nerve (LN) blocks are commonly performed using the intraoral landmark techniques. However, these methods have a risk of unanticipated nerve and arterial injury or a higher failure rate. We developed a novel extraoral approach for the IAN and LN blocks, the “inferior alveolar nerve block mandibular angle approach (IANB-MA),” using ultrasound guidance. The mechanism of action of this nerve block was examined anatomically, and its clinical feasibility was reported.We performed the IANB-MA on four cadavers using different dye volumes (2, 4, 6 and 8 mL). The ultrasound probe was placed on the lower edge of the mandibula of each cadaver, and the needle was advanced to the mandibular inner surface. Blue acrylic paint solution was injected, and its spread was evaluated by dissection.Our study showed that the medial pterygoid muscle fascia was stained in all cadavers. The dye reached the LN consistently, and the IAN was stained with higher volumes (6 mL and 8 mL). The pterygomandibular space was filled with 6 mL and 8 mL of the dye. The IANB-MA successfully reduced pain in three patients with trigeminal neuralgia, tongue or jaw pain.The IANB-MA is a novel ultrasound-guided approach to the IAN and the LN. The clinical feasibility and effectiveness of this technique were confirmed in our patients. It may be a good alternative analgesic approach to other conventional approaches.Methods: Inferior alveolar nerve (IAN) and lingual nerve (LN) blocks are commonly performed using the intraoral landmark techniques. However, these methods have a risk of unanticipated nerve and arterial injury or a higher failure rate. We developed a novel extraoral approach for the IAN and LN blocks, the “inferior alveolar nerve block mandibular angle approach (IANB-MA),” using ultrasound guidance. The mechanism of action of this nerve block was examined anatomically, and its clinical feasibility was reported.We performed the IANB-MA on four cadavers using different dye volumes (2, 4, 6 and 8 mL). The ultrasound probe was placed on the lower edge of the mandibula of each cadaver, and the needle was advanced to the mandibular inner surface. Blue acrylic paint solution was injected, and its spread was evaluated by dissection.Our study showed that the medial pterygoid muscle fascia was stained in all cadavers. The dye reached the LN consistently, and the IAN was stained with higher volumes (6 mL and 8 mL). The pterygomandibular space was filled with 6 mL and 8 mL of the dye. The IANB-MA successfully reduced pain in three patients with trigeminal neuralgia, tongue or jaw pain.The IANB-MA is a novel ultrasound-guided approach to the IAN and the LN. The clinical feasibility and effectiveness of this technique were confirmed in our patients. It may be a good alternative analgesic approach to other conventional approaches.Results: Inferior alveolar nerve (IAN) and lingual nerve (LN) blocks are commonly performed using the intraoral landmark techniques. However, these methods have a risk of unanticipated nerve and arterial injury or a higher failure rate. We developed a novel extraoral approach for the IAN and LN blocks, the “inferior alveolar nerve block mandibular angle approach (IANB-MA),” using ultrasound guidance. The mechanism of action of this nerve block was examined anatomically, and its clinical feasibility was reported.We performed the IANB-MA on four cadavers using different dye volumes (2, 4, 6 and 8 mL). The ultrasound probe was placed on the lower edge of the mandibula of each cadaver, and the needle was advanced to the mandibular inner surface. Blue acrylic paint solution was injected, and its spread was evaluated by dissection.Our study showed that the medial pterygoid muscle fascia was stained in all cadavers. The dye reached the LN consistently, and the IAN was stained with higher volumes (6 mL and 8 mL). The pterygomandibular space was filled with 6 mL and 8 mL of the dye. The IANB-MA successfully reduced pain in three patients with trigeminal neuralgia, tongue or jaw pain.The IANB-MA is a novel ultrasound-guided approach to the IAN and the LN. The clinical feasibility and effectiveness of this technique were confirmed in our patients. It may be a good alternative analgesic approach to other conventional approaches.Conclusions: Inferior alveolar nerve (IAN) and lingual nerve (LN) blocks are commonly performed using the intraoral landmark techniques. However, these methods have a risk of unanticipated nerve and arterial injury or a higher failure rate. We developed a novel extraoral approach for the IAN and LN blocks, the “inferior alveolar nerve block mandibular angle approach (IANB-MA),” using ultrasound guidance. The mechanism of action of this nerve block was examined anatomically, and its clinical feasibility was reported.We performed the IANB-MA on four cadavers using different dye volumes (2, 4, 6 and 8 mL). The ultrasound probe was placed on the lower edge of the mandibula of each cadaver, and the needle was advanced to the mandibular inner surface. Blue acrylic paint solution was injected, and its spread was evaluated by dissection.Our study showed that the medial pterygoid muscle fascia was stained in all cadavers. The dye reached the LN consistently, and the IAN was stained with higher volumes (6 mL and 8 mL). The pterygomandibular space was filled with 6 mL and 8 mL of the dye. The IANB-MA successfully reduced pain in three patients with trigeminal neuralgia, tongue or jaw pain.The IANB-MA is a novel ultrasound-guided approach to the IAN and the LN. The clinical feasibility and effectiveness of this technique were confirmed in our patients. It may be a good alternative analgesic approach to other conventional approaches. [ABSTRACT FROM AUTHOR]

This article discusses a rare condition called inverse Marcus Gunn jaw winking phenomenon (IMGJWP), which causes droopiness of the eyelid with jaw movement. The article describes a case of a 21-year-old male who presented with left upper lid droopiness while chewing, along with vision problems. The condition is characterized by an inhibitory synkinesis between the trigeminal and oculomotor nerves. The article also mentions Marin Amat syndrome (MAS), which is closely linked to IMGJWP but has different electromyography findings. The exact connection between the levator and pterygoid muscles in IMGJWP is still debated. [Extracted from the article]

Myositis ossificans (MO) is a rare disease which involve calcification of the pterygoid muscles leading to severe trismus and limited mouth opening, that is considered as difficult airway when proceeding with general anesthesia (GA). We report a case of 26-year-old parturient with an underlying MO of the pterygoid muscles, who developed postpartum hemorrhage due to retained placenta, and needed emergency manual removal of the placenta in the operating room. Providing anesthesia for these patients can present a significant challenge. Difficulty arises related to combination of airway management for GA, resuscitation and a narrow time window to commence to the surgery. Awake fiberoptic intubation is a safe method to secure the airway for such patient while multidisciplinary team effort of focused planning and resuscitation is crucial to avoid maternal morbidity and airway catastrophe. [ABSTRACT FROM AUTHOR]

Background: We conducted a narrative review of studies analyzing the occlusal and mandibular plane angles after maxillary molar distalization using temporary skeletal anchorage devices (TADs). An original preliminary investigation was conducted on the occlusal and mandibular plane angle changes according to the design of TAD-supported distalization. Methods: We included 51 participants stratified into three groups (buccal TAD, lingual arch TAD, and pendulum TAD) who underwent lateral cephalography before and after treatment. The paired t-test and ANOVA were used to analyze the significant differences among the groups. Results: The pterygoid vertical to maxillary second molar (p < 0.01) significantly differed before and after treatment within each group (group 1, 1.29 ± 1.73 mm; group 2, 2.01 ± 1.46 mm; group 3, 1.12 ± 1.43 mm). The angle between the Frankfort horizontal and anatomical occlusal plane increased by 1.96 ± 2.88° (p < 0.05) and 2.51 ± 2.57° (p < 0.01) in groups 2 and 3, respectively. Conclusions: The measured variables did not significantly differ among the three groups. The Frankfort-mandibular plane angle and functional occlusal plane did not change after maxillary molar distalization. The anatomical occlusal plane is influenced by the anterior teeth and may be unrelated to maxillary molar distalization. Further studies are required to verify the exact relationship between maxillary molar distalization and occlusal plane angle. [ABSTRACT FROM AUTHOR]

Background  Invasion depth influences the choice for extirpation of nasopharyngeal malignancies. This study aims to validate the feasibility of endoscopic endonasal resection of lesions with a posterolateral invasion. As a secondary goal, the study intends to propose a classification system of endoscopic endonasal nasopharyngectomy determined by the depth of posterolateral invasion. Methods  Eight cadaveric specimens (16 sides) underwent progressive nasopharyngectomy using an endoscopic endonasal approach. Resection of the torus tubarius, Eustachian tube (ET), medial pterygoid plate and muscle, lateral nasal wall, and lateral pterygoid plate and muscle were sequentially performed to expose the fossa of Rosenmüller, petroclival region, parapharyngeal space (PPS), and jugular foramen, respectively. Results  Technical feasibility of endonasal nasopharyngectomy toward a posterolateral direction was validated in all 16 sides. Nasopharyngectomy was classified into four types as follows: (1) type 1: resection restricted to the posterior or superior nasopharynx; (2) type 2: resection includes the torus tubarius which is suitable for lesions extended into the petroclival region; (3) type 3: resection includes the distal cartilaginous ET, medial pterygoid plate, and muscle, often required for lesions extending laterally into the PPS; And (4) type 4: resection includes the lateral nasal wall, pterygoid plates and muscles, and all the cartilaginous ET. This extensive resection is required for lesions involving the carotid artery or extending to the jugular foramen region. Conclusion  Selected lesions with posterolateral invasion into the PPS or jugular foramen is amenable to a resection via expanded endonasal approach. Classification of nasopharyngectomy based on tumor depth of posterolateral invasion helps to plan a surgical approach. [ABSTRACT FROM AUTHOR]

Presented for the first time is a reconstruction of the skull of Diadectes (Diadectomorpha) based on several specimens of a single species Diadectes absitus from the early Permian of central Germany. Since its first discovery at the end of the 19th century the only reconstructions of the skull of Diadectes were without specific designation, despite a rich Permo-Carboniferous fossil record. The skull of D. absitus is reconstructed in dorsal, lateral, posterior, and ventral views and includes exocranial and endocranial elements. The reconstructions of Diadectes presented here are compared with those of all other authors, and the differences are analysed and discussed. The comparisons recognised three features not recorded in other species of Diadectes : (1) anterior and posterior margins of the transverse process of the pterygoid parallel one another; (2) the angle between the posterior margin of the transverse process and the lateral margin of the quadrate ramus of the pterygoid is sharply defined; and (3) the anterior ventral margin of the transverse process of the pterygoid bears a distinct sharp ridge. These characters are discussed in the context of the skull anatomy of Diadectes and inaccuracies in previous cranial reconstructions of the genus are rectified. [ABSTRACT FROM AUTHOR]

Parioxys ferricolus Cope, 1878 is a long-neglected taxon of dissorophid temnospondyls from the early Permian (Cisuralian) of Texas. Reexamination of the original material and preparation of a previously undescribed specimen shed some light on the ontogeny and reveal numerous eucacopine features. P. ferricolus is characterized by: (1) a preorbital region 1.5 times as long as the posterior skull table in juveniles and twice as long in adults, (2) a parietal only two-thirds the length of the frontal, (3) interpterygoid vacuities shorter than half the skull length, (4) choanae posteriorly extended, and (5) vomer with enlarged, V-shaped median depression. P. ferricolus is found nested with Kamacops acervalis Gubin, 1980, with which it shares synapomorphies in the palate, within the dissorophid clade Eucacopinae. [ABSTRACT FROM AUTHOR]

Objective: Palatoplasty would involve the structures around the pterygoid hamulus. However, clinicians hold different opinions on the optimal approach for the muscles and palatine aponeurosis around the pterygoid hamulus. The absence of a consensus regarding this point can be attributed to the lack of investigations on the exact anatomy of this region. Therefore, we used micro-computed tomography to examine the anatomical structure of the region surrounding the pterygoid hamulus. Design: Cadaveric specimens were stained with iodine–potassium iodide and scanned by micro-computed tomography to study the structures of the tissues, particularly the muscle fibers. We imported Digital Imaging and Communications in Medicine images to Mimics to reconstruct a 3-dimensional model and simplified the model. Results: Three muscles were present around the pterygoid hamulus, namely the palatopharyngeus (PP), superior constrictor (SC), and tensor veli palatini (TVP). The hamulus connects these muscles as a key pivot. The TVP extended to the palatine aponeurosis, which bypassed the pterygoid hamulus, and linked the PP and SC. Some muscle fibers of the SC originated from the hamulus, the aponeurosis of which was wrapped around the hamulus. There was a distinct gap between the pterygoid hamulus and the palatine aponeurosis. This formed a pulley-like structure around the pterygoid hamulus. Conclusions: Transection or fracture of the palatine aponeurosis or pterygoid hamulus, respectively, may have detrimental effects on the muscles around the pterygoid hamulus, which play essential roles in the velopharyngeal function and middle ear ventilation. Currently, cleft palate repair has limited treatment options with proven successful outcomes. [ABSTRACT FROM AUTHOR]

Occlusal alteration due to tooth loss may cause overload of masticatory muscle and promote muscle dysfunction. This study explored the feasibility of using functional magnetic resonance imaging (fMRI) to evaluate muscle dysfunction in an established unilateral exodontia animal model. 6 rabbits were extracted right maxillary molars. T2 mapping, T2* mapping and Iterative Decomposition of water and fat with Echo Asymmetry and Least Square Estimation (IDEAL-IQ) were performed one day before extraction and every 2 weeks (2th~12th week) after extraction. The T2 and T2* values and fat fraction (FF) of bilateral temporal muscle (TM), masseter muscle (MM) and medial pterygoid muscle (MPM) were measured and compared between the extraction side and the contralateral side. Parameters of three monitoring time points (0th, 6th, 12th week) were also analyzed. T2 values of MM on extraction side were significantly higher than those of contralateral side-from fourth week to 12th week after extraction (p < 0.05). T2 values of MM and MPM on extraction side and TM on contralateral side were significantly higher in 12th week than those in 0th week (p < 0.05). And FF of bilateral MM was significantly higher in 12th week than those in 0th week (p < 0.05). T2* value showed no significant difference between extraction side and contralateral side and also at above three time points. T2 and T2* value and FF can be used as indicators of masticatory muscle dysfunction. fMRI is expected to be a non-invasive method for in vivo and real-time evaluation of masticatory muscle functional abnormality. [ABSTRACT FROM AUTHOR]

Purpose: Management of mandibular condylar fracture has invited a great deal of controversy in maxillofacial trauma care. In the orthopaedic literature, surgeons have exhaustively described the use of a 'hematoma block' technique during closed reduction (CR) of the ankle or other long bone fractures. Post-traumatic ankylosis of the temporomandibular joint (TMJ) is due to development and progression of the intra-articular hematoma. We improvised their technique for use during CR of mandibular condylar fractures. The desirable effects which can be achieved with our proposed 'novel TMJ hematoma nerve block' technique are evacuating the accumulated hematoma, blocking auriculotemporal and masseteric nerves which in turn causes relaxation of the lateral pterygoid muscle, all in all, favouring accurate anatomical reduction of the fracture. Method: Thirteen patients with isolated unilateral condylar fractures were subjected to our new technique. The parameters assessed were the amount of hematoma evacuated, pain in TMJ region during reduction and postoperative anatomic reduction on cone beam computed tomography (CBCT). Results: All the patients showed a significant reduction in pain and lowered post-reduction angulation between the proximal condylar and distal ramal segments. Conclusion: Our technique is minimally invasive, safe, simple to perform, yielding excellent anatomic reduction of the fracture fragments. [ABSTRACT FROM AUTHOR]

Background: Temporomandibular disorder (TMD) is the main cause of non-dental pain in orofacial area. The most common symptoms of TMD are joint pain, joint sound and limitation of jaw function. Botulinum toxin (BTX) injection is considered a potential treatment for TMD due to its pain-relieving properties and its ability to reduce muscle activity. Most of the studies are case series and further investigations are required to prove the efficacy of this treatment modality. Thus, in this study, we aimed to investigate the effect of BTX-A injection on the lateral pterygoid (LP) muscle and to evaluate its efficacy regarding TMD. Materials and methods: Thirty-eight patients (19 women and 19 men; mean age of 26.53 years) with painful unilateral temporomandibular joint click and LP muscle tenderness were enrolled in this study. They were divided into two groups; one received an extraoral BTX-A injection in the LP muscle, and the other received a placebo injection. Pain severity, jaw movements, click severity, and Helkimo index were recorded at the first visit, as well as one week, one month, and three months after the intervention. Data were analyzed using repeated-measures analysis of variance and t-tests. Results: The results showed that click severity was not significantly different between the BTX-A and placebo groups (P = 0.07). Pain and Helkimo index decreased significantly in the BTX group (P = 0.00 and P = 0.006, respectively); however, there was no significant difference between the two groups (P = 0.22 and P = 1, respectively). There was a significant difference in lateral movements between the groups (P = 0.00) but not in protrusive movement (P = 0.095). Conclusions: It can be concluded that although some studies have stated that BTX injection can make the click sound disappear, in this study, we did not find a significant difference between the two groups. Furthermore, our results showed that click and pain severity decreased, but the difference was not statistically significant. Therefore, further studies with a higher dosage of BTX and more participants are recommended. Trial registration The local Ethics Committee of Shiraz University of Medical Sciences approved this research (IR.SUMS.REC. 01/10/2018 and IRCT20130521013406N3). [ABSTRACT FROM AUTHOR]